Forty normally intelligent girls, aged 7 to 10 years, referred for attention, learning, and hyperkinetic disorders, will be studied on several dimensions hypothesized to be related to CNS strength or weakness: agumentation-reduction, impulsivity-reflectivity, field dependence-independence, leveling-sharpening, flexibility-constrictivity. The clinical cases will be categorized (10 in each group) as "pure" hyperactives, "pure" reading disabled, "mixed types" (both hyperactive and reading disabled), or attention disordered (neither hyperactive nor reading disabled but nonproductive students) and contrasted with 10 female controls as well as with similar groups of boys who participated in an earlier study. Preliminary analyses suggest the hyperactive subjects (both sexes) have the weakest or more sensitive nervous systems while attention disordered subjects are perhaps too insensitive to potent stimuli. Girls rate themselves more intolerant of discomforts than boys but the sexes do not differ significantly or any other measures listed above, nor do the diagnostic groups. Cognitive style measures cluster more cohesively in the boys than girls. The reading disabled girls have lower IQs and significantly less discrepancy between IQ and WRAT reading-spelling standard scores than the reading disabled boys.